Claim of Priority under 35 U.S.C. §119
[0001] The present Application for Patent claims priority to Provisional Application Serial
No.
60/834,118, entitled "METHOD AND APPARATUS FOR PREAMBLE CONFIGURATION IN WIRELESS COMMUNICATION
SYSTEMS," filed July 28, 2006, assigned to the assignee hereof.
BACKGROUND
Field
[0002] The present disclosure relates generally to communication, and more specifically
to techniques for sending signaling in a wireless communication system.
Background
[0003] Wireless communication systems are widely deployed to provide various communication
services such as voice, video, packet data, messaging, broadcast, etc. These systems
may be multiple-access systems capable of supporting multiple users by sharing the
available system resources. Examples of such multiple-access systems include Code
Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems,
Frequency Division Multiple Access (FDMA) systems, Orthogonal FDMA (OFDMA) systems,
and Single-Carrier FDMA (SC-FDMA) systems.
[0004] A base station may transmit data to one or more terminals on the forward link and/or
receive data from one or more terminals on the reverse link at any given moment. The
base station may send signaling to indicate which terminals are scheduled for data
transmission and to convey information pertinent to receive the data transmission.
It is desirable to send the signaling as efficiently as possible since this signaling
represents overhead. Furthermore, it is desirable to send the signaling such that
the terminals can reliably receive the signaling.
[0005] There is therefore a need in the art for techniques to efficiently and reliably send
signaling in a wireless communication system.
[0006] EP 1638271 and XP002493410 both disclose a method and an apparatus to transmit both signaling
and data in a wireless OFDM communications system.
SUMMARY
[0007] Techniques for sending signaling for data transmission in a wireless communication
system are described herein. In one aspect, a transmitter (e.g., a base station) may
process signaling for a data transmission based on a block code, a convolutional code,
a transformation, etc. The signaling may comprise an identifier of an intended receiver
(e.g., an access terminal) of the data transmission and/or other information such
as data rate, resource assignment, etc., for the data transmission. The signaling
for the data transmission may be mapped to a first set of tones in a time slot. Data
for the data transmission may be mapped to a second set of tones in the time slot.
The first and second sets of tones may be among the tones assigned for the data transmission,
which may be all or a subset of the tones available for use. The entire signaling
may be sent on the first set of tones. Alternatively, the first set of tones may be
selected from among multiple sets of tones or pseudo-randomly selected from among
the assigned tones based on a first part of the signaling. A second part of the signaling
may then be sent on the first set of tones. The number of tones in the first set and/or
the transmit power for the signaling may be selected based on channel conditions.
[0008] In another aspect, the receiver (e.g., the access terminal) may obtain received symbols
for the first set of tones in the time slot and may process the received symbols to
obtain detected signaling. The receiver may determine whether or not to process the
second set of tones in the time slot for the data transmission based on the detected
signaling. If the detected signaling indicates that data transmission is sent, then
the receiver may determine the second of tones based on the detected signaling and
may further process received symbols for the second set of tones (e.g., based on the
data rate from the detected signaling) to recover the transmitted data.
[0009] Various aspects and features of the disclosure are described in further detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010]
FIG. 1 shows a wireless communication system.
FIG. 2 shows an example slot structure.
FIG. 3 shows a tone structure for sending signaling.
FIGS. 4A to 4D show four additional tone structures for sending signaling.
FIG. 5 shows a block diagram of an access point and an access terminal.
FIG. 6 shows a block diagram of a transmit processor and an OFDM modulator.
FIG. 7 shows a signaling processor that sends signaling in multiple parts.
FIG. 8 shows a block diagram of a transmit processor according to one embodiment.
FIG. 9 shows a signaling processor that sends signaling on a selected set of tones.
FIG. 10 shows a signaling processor that spreads signaling symbols across tones.
FIG. 11 shows a signaling processor that sends signaling on pseudo-randomly selected
tones.
FIG. 12 shows a block diagram of an OFDM demodulator and a receive processor.
FIG. 13 shows a process for transmitting data and signaling.
FIG. 14 shows a process for sending signaling.
FIG. 15 shows a process for receiving data and signaling.
DETAILED DESCRIPTION
[0011] The transmission techniques described herein may be used for various wireless communication
systems such as CDMA, TDMA, FDMA, OFDMA, and SC-FDMA systems. The terms "system" and
"network" are often used interchangeably. A CDMA system may implement a radio technology
such as cdma2000, Universal Terrestrial Radio Access (UTRA), etc. cdma2000 covers
IS-2000, IS-95 and IS-856 standards. UTRA includes Wideband CDMA (W-CDMA) and Low
Chip Rate (LCR). A TDMA system may implement a radio technology such as Global System
for Mobile Communications (GSM). An OFDMA system may implement a radio technology
such as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi),
IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM®, etc. These various radio technologies
and standards are known in the art. UTRA, E-UTRA and GSM are described in documents
from an organization named "3rd Generation Partnership Project" (3GPP). cdma2000 is
described in documents from an organization named "3rd Generation Partnership Project
2" (3GPP2).
[0012] For clarity, certain aspects of the transmission techniques are described below for
a High Rate Packet Data (HRPD) system that implements IS-856. HRPD is also referred
to as Evolution-Data Optimized (EV-DO), Data Optimized (DO), High Data Rate (HDR),
etc. For clarity, HRPD terminology is used in much of the description below.
[0013] FIG. 1 shows a wireless communication system 100 with multiple access points 110 and multiple
access terminals 120. An access point is generally a fixed station that communicates
with the access terminals and may also be referred to as a base station, a Node B,
etc. Each access point 110 provides communication coverage for a particular geographic
area 102 and supports communication for the access terminals located within the coverage
area. Access points 110 may couple to a system controller 130 that provides coordination
and control for these access points. System controller 130 may include one or more
network entities such as a Base Station Controller (BSC), a Packet Control Function
(PCF), a Packet Data Serving Node (PDSN), etc.
[0014] Access terminals 120 may be dispersed throughout the system, and each access terminal
may be stationary or mobile. An access terminal may also be referred to as a terminal,
a mobile station, a user equipment, a subscriber unit, a station, etc. An access terminal
may be a cellular phone, a personal digital assistant (PDA), a wireless device, a
handheld device, a wireless modem, a laptop computer, etc. In HRPD, an access terminal
may receive data transmission on the forward link from one access point at any given
moment and may send data transmission on the reverse link to one or more access points.
The forward link (or downlink) refers to the communication link from the access points
to the access terminals, and the reverse link (or uplink) refers to the communication
link from the access terminals to the access points.
[0015] FIG. 2 shows a slot structure 200 that may be used for transmission on the forward link.
The transmission timeline may be partitioned into slots. Each slot may have a predetermined
time duration. In one design, each slot has a duration of 1.667 milliseconds (ms)
and spans 2048 chips, with each chip having a duration of 813.8 nanoseconds (ns) for
a chip rate of 1.2288 megachips/second (Mcps). Each slot may be divided into two identical
half-slots. Each half-slot may include (i) an overhead segment composed of a pilot
segment at the center of the half-slot and two Media Access Control (MAC) segments
on both sides of the pilot segment and (ii) two traffic segments on both sides of
the overhead segment. The traffic segments may also be referred to as a traffic channel,
data segments, data fields, etc. The pilot segment may have a duration of 96 chips
and may carry pilot that may be used for initial acquisition, frequency and phase
recovery, timing recovery, channel estimation, radio combining, etc. Each MAC segment
may have a duration of 64 chips and may carry signaling such as, e.g., reverse power
control (RPC) information, channel structure, frequency, transmit power, coding and
modulation, etc. Each traffic segment may have a duration of 400 chips and may carry
traffic data (e.g., unicast data for specific access terminals, broadcast data, etc.)
and/or signaling.
[0016] It may be desirable to use orthogonal frequency division multiplexing (OFDM) and/or
single-carrier frequency division multiplexing (SC-FDM) for the traffic segments.
OFDM and SC-FDM partition the system bandwidth into multiple orthogonal subcarriers,
which are also referred to as frequency bins, etc. Each subcarrier may be modulated
with data. In general, modulation symbols are sent in the frequency domain with OFDM
and in the time domain with SC-FDM. OFDM and SC-FDM have certain desirable characteristics
such as the ability to readily combat intersymbol interference (ISI) caused by frequency
selective fading. OFDM can also efficiently support multiple-input multiple-output
(MIMO) and Spatial Division Multiple Access (SDMA), which may be applied independently
on each subcarrier. For clarity, the use of OFDM for sending data and signaling in
the traffic segments is described below.
[0017] It may also be desirable to support OFDM while retaining backward compatibility with
earlier HRPD Revisions. In HRPD, the pilot and MAC segments may be demodulated by
all active terminals at all times whereas the traffic segments may be demodulated
by only the terminals being served. Hence, backward compatibility may be achieved
by retaining the pilot and MAC segments and modifying the traffic segments.
[0018] FIG. 2 shows a design that supports OFDM using the HRPD slot structure. In this design,
R OFDM symbols may be sent in a slot, or R/4 OFDM symbols per traffic segment, where
R may be any suitable integer value. In general, OFDM symbols may be generated based
on various OFDM symbol numerologies. Each OFDM symbol numerology is associated with
specific values for pertinent parameters such as OFDM symbol duration, number of subcarriers,
cyclic prefix length, etc. Table 1 lists three OFDM symbol numerologies and gives
the parameter values for each numerology, in accordance with one design.
Table 1
|
Numerology |
|
Parameter |
|
1 |
2 |
3 |
Unit |
Number of subcarriers |
N |
180 |
90 |
360 |
|
Cyclic prefix length |
C |
20 |
10 |
40 |
chips |
OFDM symbol duration |
|
200 |
100 |
400 |
chips |
Number of OFDM symbols |
R |
8 |
16 |
4 |
per slot |
Number of tones |
T |
1440 |
1440 |
1440 |
per slot |
[0019] In the design shown in Table 1, each slot may include a total of T = 1440 tones.
A tone may correspond to one subcarrier in one symbol period and may be used to send
one modulation symbol. A tone may also be referred to as a resource element, a transmission
unit, etc. Some of the T tones may be reserved for pilot, and the remaining tones
may be used for data and/or signaling.
[0020] An access point may send data to one or more access terminals in each slot. The access
point may also send signaling in each slot. The signaling may also be referred to
as preamble, scheduling information, control information, overhead information, etc.
In general, the signaling may comprise any information to support data transmission
on the forward and/or reverse links. The signaling may be for any number of access
terminals and comprise any type of information.
[0021] In one design, the signaling may comprise information indicating which access terminal(s)
are scheduled for data transmission on the forward link in a given slot. The signaling
may also comprise information for parameters pertinent to the scheduled terminal(s)
to receive the data transmission sent on the forward link. For example, the signaling
may comprise information related to the data rate used for a scheduled access terminal.
This access terminal may estimate the forward link channel quality for the access
point and may determine a data rate for data transmission to the access terminal based
on the estimated channel quality and/or other factors. The access terminal may send
this data rate on a data rate control (DRC) channel to the access point. The access
point may use the data rate sent by the access terminal or may select another data
rate. The access point may send a rate adjustment that may indicate the difference
(if any) between the data rate selected by the access point and the data rate provided
by the access terminal. The rate adjustment may allow the access point to overwrite
the DRC feedback from the access terminal. The rate adjustment may also provide the
access terminal with the actual data rate used by the access point, so that the access
terminal can avoid having to decode for different possible data rates that can be
used for data transmission.
[0022] In one design, the signaling for a scheduled access terminal may include the following:
- 8-bit MAC_ID of the scheduled access terminal, and
- 2-bit rate adjustment for the scheduled access terminal.
[0023] The access terminals communicating with the access point may be assigned unique MAC_IDs.
Each access terminal may then be identified by its MAC_ID. The access terminals may
also be identified based on other types of identifiers.
[0024] In another design, the signaling for a scheduled access terminal may include the
following:
- 8-bit MAC_ID of the scheduled access terminal,
- 2-bit rate adjustment for the scheduled access terminal,
- 2-bit assignment size indicator, and
- 1-bit sticky assignment indicator.
[0025] The scheduled access terminal may be assigned a variable amount of resources for
data transmission. The assignment size indicator may convey the amount of resources
assigned to the access terminal for the data transmission. In one design, resources
may be granted in units of tile, with each tile including a predetermined number of
tones. For example, a slot may be partitioned into 6 tiles, and each tile may include
240 tones. The access terminal may be assigned 1, 2, 4 or 6 tiles, which may be conveyed
by the 2-bit assignment size indicator. The specific tile(s) assigned to the access
terminal may be determined based on the location of the signaling and/or conveyed
by other means. The sticky assignment indicator may be set to 1 to indicate that the
current resource assignment is ongoing or to 0 to indicate that the current resource
assignment terminates after the current slot. The use of the sticky assignment indicator
may avoid the need to send the same signaling in each slot for the same continuing
resource assignment.
[0026] The signaling for a scheduled access terminal may be sent in various manners. In
one design, the signaling may be sent in OFDM symbols during the traffic segments.
The signaling may be sent on tones distributed across the system bandwidth to achieve
frequency diversity and/or across multiple symbol periods to achieve time diversity.
[0027] FIG. 3 shows a design of a tone structure 300 for sending signaling based on the 200-chip
numerology 2 in Table 1. In this design, the signaling for an access terminal may
be sent on a set of K tones that may be distributed across the entire system bandwidth
and across one half-slot. In general, the set may include any number of tones, and
K may be any value. The number of tones (K) may be selected based on a tradeoff between
signaling overhead and signaling reliability. In one design, the set may include K
= 32 tones, which may be arranged in eight tones per symbol period for the 200-chip
numerology 1 in Table 1 (as shown in FIG. 3), or four tones per symbol period for
the 100-chip numerology 2, or 16 tones per symbol period for the 400-chip numerology
3. The tones may occupy different subcarriers in different OFDM symbol periods to
increase frequency diversity, as shown in FIG. 3. In general, sending the signaling
earlier in the slot may allow the access terminal to receive the signaling sooner
and start preparing for processing the data transmission earlier. The signaling may
thus be sent in the first OFDM symbol, the first traffic segment, the first half-slot,
etc.
[0028] FIG. 4A shows a design of a signaling tone structure using 4 × 4 tiles. Each 4 × 4 tile may
be composed of two 4 × 2 tiles occupying the same four subcarriers in two traffic
segments. In this design, the signaling for an access terminal may be sent on 32 tones
in two 4 × 4 tiles located in two half-slots.
[0029] FIG. 4B shows a design of a signaling tone structure using 8 × 2 tiles. In this design, the
signaling for an access terminal may be sent on 32 tones in two 8×2 tiles located
in two half-slots. Each tile may cover eight subcarriers and span the first two symbol
periods in one half-slot.
[0030] FIG. 4C shows a design of a signaling tone structure using 16 × 1 tiles. In this design,
the signaling for an access terminal may be sent on 32 tones in two 16 × 1 tiles located
in two half-slots. Each tile may cover 16 subcarriers and span the first symbol period
in one half-slot.
[0031] FIG. 4D shows a design of a signaling tone structure using 1 × 1 tiles. In this design, the
signaling for an access terminal may be sent on 32 tones in 32 1×1 tiles located across
the two half-slots. Each tile may cover one subcarrier and span one symbol period.
[0032] FIGS. 3 through 4D show some example tone structures for sending signaling on K =
32 tones. Other tone structures may also be defined for sending signaling on different
numbers of tones (e.g., K = 16, 64, 128, etc.) and/or with different distributions
of the K tones across frequency and time. Placing the K tones closer together in frequency
and time may improve orthogonality among possible codewords sent for the signaling,
which may improve decoding performance. Distributing the K tones across frequency
and time may improve diversity. Signaling may be sent based on any tone structure
selected for use.
[0033] In one design, the signaling for a scheduled access terminal may be sent on a designated
set of tones among all tones assigned to the access terminal for data transmission.
This designated set of tones may be fixed for a given slot but may change from slot
to slot.
[0034] In another design, the signaling for a scheduled access terminal may be sent on one
of multiple (S) sets of tones. The S sets may be defined based on all tones that may
be used to send the signaling, e.g., all tones assigned to the access terminal for
data transmission. The S sets may be disjoint so that each tone belongs in at most
one set. The number of sets (S) may be dependent on the number of available tones
and the number of tones (K) in each set. In one design, S = 16 sets of tones may be
formed for the left half-slot based on the numerologies shown in Table 1, with each
set including K = 32 tones. One of the S sets may be selected for use based on a first
part of the signaling, and the selected set of tones may be used to send a remainder
part of the signaling. The signaling may puncture (or replace) data on the selected
set of tones.
[0035] FIG. 5 shows a block diagram of a design of an access point 110x and an access terminal
120x, which are one of the access points and access terminals in FIG. 1. For simplicity,
only processing units for transmission on the forward link are shown in FIG. 5. Also
for simplicity, access point 110x and access terminal 120x are each shown with one
antenna. In general, each entity may be equipped with any number of antennas.
[0036] At access point 110x, a transmit processor 510 may receive traffic data for one or
more scheduled access terminals and signaling for the scheduled access terminal(s).
Transmit processor 510 may process (e.g., encode, interleave, and symbol map) the
traffic data, pilot, and signaling and provide data symbols, pilot symbols, and signaling
symbols, respectively. A data symbol is a symbol for traffic data, a pilot symbol
is a symbol for pilot, a signaling symbol is a symbol for signaling, and a symbol
is typically a complex value. An OFDM modulator (Mod) 520 may receive the data, pilot,
and signaling symbols from transmit processor 510, perform OFDM modulation on these
symbols, and provide output samples for OFDM. A transmit processor 512 may receive
and process traffic data, pilot, and/or overhead information to be sent with CDM.
A CDM modulator 522 may perform CDM modulation on the output of transmit processor
512 and provide output samples for CDM. A multiplexer (Mux) 524 may multiplex the
output samples from modulators 520 and 522, provide the output samples from OFDM modulator
520 during time periods in which OFDM symbols are sent (or OFDM time periods), and
provide the output samples from CDM modulator 522 during time periods in which CDM
data is sent (or CDM time periods). A transmitter (TMTR) 526 may process (e.g., convert
to analog, amplify, filter, and frequency upconvert) the output samples from multiplexer
524 and generate a forward link signal, which may be transmitted via an antenna 528.
[0037] At access terminal 120x, an antenna 552 may receive the forward link signal from
access point 110x and provide a received signal to a receiver (RCVR) 554. Receiver
554 may process (e.g., filter, amplify, frequency downconvert, and digitize) the received
signal and provide received samples. A demultiplexer (Demux) 556 may provide the received
samples in OFDM time periods to an OFDM demodulator (Demod) 560 and may provide the
received samples in CDM time periods to a CDM demodulator 562. OFDM demodulator 560
may perform OFDM demodulation on the received samples and provide received signaling
symbols and received data symbols, which are estimates of the signaling symbols and
data symbols sent by access point 110x to access terminal 120x. A receive processor
570 may process the received signaling symbols to obtain detected signaling for access
terminal 120x. Receive processor 570 may also process the received data symbols to
obtain decoded data for access terminal 120x. CDM demodulator 562 may perform CDM
demodulation on the received samples. A receive processor 572 may process the output
of CDM demodulator 562 to recover information sent by access point 110x to access
terminal 120x. In general, the processing by access terminal 120x is complementary
to the processing by access point 110x.
[0038] Controllers/processors 530 and 580 may direct the operation at access point 110x
and access terminal 120x, respectively. Memories 532 and 582 may store program codes
and data for access point 110x and terminal 120x, respectively.
[0039] FIG. 6 shows a block diagram of a design of transmit processor 510 and OFDM modulator 520
at access point 110x in FIG. 5. Within transmit processor 510, a signaling processor
610 may process signaling for one or more scheduled access terminals and provide signaling
symbols. A traffic processor 620 may process traffic data for the scheduled access
terminal(s) and provide data symbols. A pilot processor 630 may process pilot and
provide pilot symbols. A tone mapper 640 may receive the signaling, data, and pilot
symbols and map these symbols to the proper tones. In each symbol period, tone mapper
640 may provide N symbols for N subcarriers to OFDM modulator 520.
[0040] Within OFDM modulator 520, an inverse discrete Fourier transform (IDFT) unit 650
may perform an N-point IDFT on the N symbols for the N subcarriers and provide a useful
portion containing N time-domain samples. A cyclic prefix generator 652 may append
a cyclic prefix by copying the last C samples of the useful portion and appending
these C samples to the front of the useful portion. A windowing/pulse shaping filter
654 may filter the samples from generator 652 and provide an OFDM symbol composed
of N + C samples, where N and C are dependent on the numerology selected for use.
[0041] For clarity, the processing of signaling for one scheduled access terminal (e.g.,
access terminal 120x) is described below. The signaling may include P bits, where
P may be any integer value. In one design, the signaling may include P = 10 bits and
comprise an 8-bit MAC_ID and a 2-bit rate adjustment. In another design, the signaling
may include P = 13 bits and comprise an 8-bit MAC_ID, a 2-bit rate adjustment, a 2-bit
assignment size indicator, and a 1-bit sticky assignment indicator.
[0042] FIG. 7 shows a block diagram of a transmit processor 510a, which is one design of transmit
processor 510 in FIG. 6. In this design, the signaling for access terminal 120x may
be partitioned into two parts and sent on two subsets of tones. One subset may include
K
1 tones, and the other subset may include K
2 tones, where K = K
1 + K
2. Within a signaling processor 610a, which is one design of signaling processor 610
in FIG. 6, a block encoder 710a may encode M most significant bits (MSBs) of the signaling
with a (K
1, M) block code and provide K
1 code bits. A symbol mapper 712a may map the K
1 code bits to K
1 modulation symbols, e.g., based on BPSK. A gain unit 714a may scale the K
1 modulation symbols to obtain the desired transmit power for the signaling and provide
K
1 signaling symbols. A block encoder 710b may encode L least significant bits (LSBs)
of the signaling with a (K
2, L) block code and provide K
2 code bits. A symbol mapper 712b may map the K
2 code bits to K
2 modulation symbols. A gain unit 714b may scale the K
2 modulation symbols to obtain the desired transmit power for the signaling and provide
K
2 signaling symbols. In one design, M = L = 5, K
1 = K
2 = 16, and each block encoder 710 may implement a (16, 5) block code. Other values
may also be used for M, L, K
1 and K
2.
[0043] In one design, an orthogonal code may be used for the signaling and may map a B-bit
signaling value to a 2
B-bit codeword. For example, a Walsh code may map four possible 2-bit signaling values
to codewords of 0000, 0101, 0011 and 0110. In another design, a bi-orthogonal code
may be used for the signaling and may map a B-bit signaling value to a 2
B-1-bit codeword. For example, a bi-orthogonal code may map four possible 2-bit signaling
values to codewords of 00, 11, 01 and 10. A B-bit bi-orthogonal code may use all codewords
in a (B-1)-bit orthogonal code as well as the complementary codewords. Other codes
may also be used for the signaling, as described below.
[0044] The partitioning of the signaling into multiple parts may allow for reduction of
the number of tones used to send the signaling when encoded with an orthogonal code
or a bi-orthogonal code. For example, an orthogonal code may map a 10-bit signaling
value to a 1024-bit codeword. This 10-bit signaling may be partitioned into two 5-bit
parts, each 5-bit part may be mapped to a 32-bit codeword, and a total of 64 bits
may be generated for the 10-bit signaling value. The partitioning of the signaling
into multiple parts may be based on various considerations such as the number of signaling
bits to send, the number of tones to use for the signaling, the desired coding gain,
detection performance, etc.
[0045] Within traffic processor 620, an encoder 720 may encode the traffic data for scheduled
access terminal 120x based on the data rate selected for the access terminal and provide
code bits. A symbol mapper 722 may map the code bits to modulation symbols based on
a modulation scheme determined by the selected data rate. A gain unit 724 may scale
the modulation symbols to obtain the desired transmit power for the traffic data and
provide data symbols. Within pilot processor 630, a pilot generator 730 may generate
symbols for pilot. A gain unit 734 may scale the symbols from generator 730 to obtain
the desired transmit power for pilot and provide pilot symbols. A tone mapper 640a
may map the 32 signaling symbols from processor 610a to the 32 tones used for signaling,
map the data symbols from processor 620 to tones used for traffic data, and map the
pilot symbols from processor 630 to tones used for pilot.
[0046] The signaling may also be partitioned into more than two parts, encoded separately,
and sent on more than two subsets of tones. In one design, 13-bit signaling for access
terminal 120x may be partitioned into three parts - a first 4-bit part that may be
encoded with an (8, 4) block code and mapped to 8 tones, a second 4-bit part that
may also be encoded with the (8, 4) block code and mapped to another 8 tones, and
a third 5-bit part that may be encoded with a (16, 5) block code and mapped to another
16 tones. In another design, the 13-bit signaling may be partitioned into four parts
- a first 3-bit part that may be encoded with a (4, 3) block code and mapped to four
tones, a second 3-bit part that may also be encoded with the (4, 3) block code and
mapped to another four tones, a third 3-bit part that may also be encoded with the
(4, 3) block code and mapped to another four tones, and a fourth 4-bit part that may
be encoded with an (8, 4) block code and mapped to another eight tones. The signaling
may also be encoded with a single block code and sent on one set of tones.
[0047] FIG. 8 shows a block diagram of a transmit processor 510b, which is another design of transmit
processor 510 in FIG. 6. In this design, the signaling for access terminal 120x may
be sent on one of S possible sets of tones, with each set including K tones, where
S and K may be any integer values. Within a signaling processor 610b, which is another
design of signaling processor 610 in FIG. 6, a block encoder 810 may encode L LSBs
of the signaling with a (K, L) block code and provide K code bits. A symbol mapper
812 may map the K code bits to K modulation symbols. A gain unit 814 may scale the
K modulation symbols and provide K signaling symbols. A selector 816 may receive M
MSBs of the signaling and select one of S possible sets of tones based on the M MSBs,
where S ≥ 2
M. A tone mapper 640b may map the K signaling symbols from processor 610b to the K
tones in the selected set and may map the data and pilot symbols to tones used for
traffic data and pilot, respectively.
[0048] Table 2 gives some example designs of signaling processor 610b in FIG. 8. These designs
assume that the signaling includes P = 10 bits, a total of 512 tones may be used to
send the signaling, and BPSK is used for the signaling. Other values may also be used
for S, K, M and/or L for other signaling sizes, other modulation schemes, etc. For
example, QPSK may be used instead of BPSK, and the number of tones may be reduced
by half.
Table 2
Set Size |
Num of tone sets S |
Num of tones/set K |
Num of MSBs M |
Num of LSBs L |
Block Code (K, L) |
256-tone set |
2 |
256 |
1 |
9 |
(256, 9) |
128-tone set |
4 |
128 |
2 |
8 |
(128, 8) |
64-tone set |
8 |
64 |
3 |
7 |
(64, 7) |
32-tone set |
16 |
32 |
4 |
6 |
(32, 6) |
16-tone set |
32 |
16 |
5 |
5 |
(16, 5) |
8-tone set |
64 |
8 |
6 |
4 |
(8, 4) |
4-tone set |
128 |
4 |
7 |
3 |
(4, 3) |
[0049] Sending the signaling on one of multiple sets of tones may provide certain advantages.
Some signaling bits may be sent via the specific set of tones selected for use, and
the remaining signaling bits may be sent on the selected set of tones. The number
of sets and the number of tones in each set may be selected based on various considerations
such as the number of signaling bits to send, the number of tones available to send
the signaling, the desired coding gain, detection performance, etc.
[0050] FIG. 9 shows a block diagram of a transmit processor 510c, which is yet another design of
transmit processor 510 in FIG. 6. In this design, the signaling for access terminal
120x may be sent on one of S possible sets of tones, with each set including K tones.
Within a signaling processor 610c, which is yet another design of signaling processor
610 in FIG. 6, a block encoder 910 may encode L LSBs of the signaling with a block
code and provide code bits. A symbol mapper 912 may map the code bits to K modulation
symbols. A discrete Fourier transform (DFT) unit 914 may transform the K modulation
symbols with a K-point DFT and provide K frequency-domain symbols. Unit 914 may also
be replaced with some other unitary transformation (with non-zero entries) that can
spread each modulation symbol across all or many of the tones. A gain unit 916 may
scale the frequency-domain symbols and provide K signaling symbols. A selector 918
may receive M MSBs of the signaling and select one of S sets of tones based on the
M MSBs. A tone mapper 640d may map the K signaling symbols from processor 610c to
the K tones for the selected set and may map the data and pilot symbols to tones used
for traffic data and pilot, respectively.
[0051] The DFT processing by unit 914 may provide frequency diversity for the L LSBs of
the signaling. Equalization may be used at the receiver to improve performance.
[0052] In the designs shown in FIGS. 8 and 9, the MAC_ID may be sent in the MSB portion
of the signaling. In this case, each access terminal may be mapped to one of the S
possible sets of tones based on its MAC_ID. Each access terminal may then detect for
signaling on only its assigned set of tones.
[0053] FIG. 10 shows a block diagram of a transmit processor 510d, which is yet another design of
transmit processor 510 in FIG. 6. In this design, the signaling for access terminal
120x may be sent on a set of K tones. Within a signaling processor 610d, which is
yet another design of signaling processor 610 in FIG. 6, a cyclic redundancy check
(CRC) generator 1010 may generate a CRC for the signaling. The CRC may be used for
error detection by access terminal 120x. A convolutional encoder 1012 may encode the
CRC and signaling and provide code bits. A puncture unit 1014 may puncture or delete
some of the code bits to obtain the desired number of code bits. A symbol mapper 1016
may map the code bits from unit 1014 to K modulation symbols. A gain unit 1018 may
scale the modulation symbols and provide K signaling symbols. A tone mapper 640d may
map the K signaling symbols from processor 610d to the K tones for the selected set
and may map the data and pilot symbols to tones used for traffic data and pilot, respectively.
[0054] In one design, CRC generator 1010 may generate a 10-bit CRC for 10-bit signaling.
Convolutional encoder 1012 may append 8 tail bits and then encode the 28 total bits
with a rate 1/3 convolutional code to obtain 84 code bits. Puncture unit 1014 may
puncture 20 of the 84 code bits and provide 64 code bits. Symbol mapper 1016 may map
the 64 code bits to 32 QPSK modulation symbols, which may be mapped to K = 32 tones.
Other values may also be used for signaling processor 610d.
[0055] FIG. 11 shows a block diagram of a transmit processor 510e, which is yet another design of
transmit processor 510 in FIG. 6. In this design, the signaling for access terminal
120x may be sent on K tones that may be pseudo-randomly selected from among all tones
assigned to access terminal 120x.
[0056] Within a signaling processor 610e, which is yet another design of signaling processor
610 in FIG. 6, a block encoder 1110 may encode L LSBs of the signaling with a block
code and provide code bits. A symbol mapper 1112 may map the code bits to K modulation
symbols. A gain unit 1114 may scale the K modulation symbols and provide K signaling
symbols. A tone selector 1116 may receive M MSBs of the signaling and possibly other
information such as a cell_ID, a slot index, etc. Selector 1116 may pseudo-randomly
select K tones from among all tones assigned to access terminal 120x based on the
inputs. A tone mapper 640e may map the K signaling symbols from processor 610e to
the K pseudo-randomly selected tones and may map the data and pilot symbols to tones
used for traffic data and pilot, respectively.
[0057] In the design shown in FIG. 11, the signaling may be sent using "flash" techniques,
which send information on a small number of tones with (e.g., 6 dB or more) higher
transmit power than traffic transmit power. Collision between the signaling for different
access terminals in the same cell may be avoided by sending the signaling for each
access terminal on the tones assigned to that access terminal. Collision between the
signaling for different access terminals in different cells may be reduced by pseudo-randomly
selecting the tones. In one design, the M MSBs may include the 8-bit MAC ID, and the
L LSBs may include the remaining part of the signaling. For the 10-bit signaling design
described above, the L LSBs may include the 2-bit rate adjustment, and K = 2 tones
may be pseudo-randomly selected and used to send the signaling. For the 13-bit signaling
design described above, the L LSBs may include the 2-bit rate adjustment, the 2-bit
assignment size indicator, and the 1-bit sticky assignment indicator, and K = 5 tones
may be pseudo-randomly selected and used to send the signaling. The tones may also
be selected from among a designated group of tones, from all tones in the slot, etc.
[0058] FIGS. 7 through 11 show some example designs of signaling processor 610 in FIG. 6.
Signaling processor 610 may also be implemented with other designs.
[0059] In some designs described above, the entire signaling or part of the signaling may
be encoded with one or more block encoders to generate code bits. In one design, the
signaling may be encoded with one or more static block encoders. A static block encoder
has a predetermined codebook and maps each possible signaling value to one specific
codeword or output value. A static block encoder may implement any block code known
in the art such as an orthogonal code, a bi-orthogonal code, a Hamming code, a Reed-Muller
code, a Reed-Solomon code, a repetition code, etc.
[0060] In another design, the signaling may be encoded with one or more dynamic block encoders.
A dynamic block encoder has a time-varying codebook that changes over time. For example,
the codebook may change from slot to slot, and a given signaling value may be mapped
to different codewords in different slots. A dynamic block encoder may implement a
pseudo-random codebook, which may be derived based on a pseudo-random number (PN)
sequence. Each access terminal may be assigned a unique 48-bit PN sequence that may
be updated at the start of each slot. Sixteen codewords of length 32 may be defined
based on the 48-bit PN sequence, e.g., the
m-th codeword may comprise bits
m through
m + 31 of the PN sequence, where
m = 0, 1, ...,15. The correlation between any two codewords in the pseudo-random codebook
would be small due to the pseudo-random nature of the PN sequence. Different codebooks
may be used for different access terminals and generated based on their different
PN sequences. Furthermore, the codebook for each access terminal may vary over time
based on the PN sequence of that access terminal. These codebooks may be generated
easily by the access point and each access terminal. The use of pseudo-random codebooks
may reduce false alarm under certain channel conditions. A false alarm is declaration
of a codeword when none was sent or signaling is intended for a different access terminal.
[0061] The signaling for access terminal 120x may be sent in an adaptive manner based on
channel conditions to ensure reliable reception of the signaling by access terminal
120x. In one design, the signaling may be sent in a variable number of tones, which
may be determined based on the channel conditions. The channel conditions may be ascertained,
e.g., based on the DRC feedback from access terminal 120x. In general, more tones
may be used for poor channel conditions (e.g., low SNR), and fewer tones may be used
for good channel conditions (e.g., high SNR). In one design, the signaling may be
sent on 8, 16, 32, 64, 128, 256 or 512 tones depending on the channel conditions,
e.g., the DRC feedback. The signaling may be sent at a fixed signaling-to-pilot power
ratio.
[0062] In another design, the signaling for access terminal 120x may be sent in a fixed
number of tones, but the transmit power for the signaling may be varied based on the
channel conditions. In general, more transmit power (or higher signaling gain) may
be used for poor channel conditions, and less transmit power (or lower signaling gain)
may be used for good channel conditions. The signaling transmit power may be a function
of the DRC feedback.
[0063] The signaling for access terminal 120x may be sent from one or multiple antennas
at the access point. In one design, the signaling may be sent from one antenna even
when multiple transmit antennas are available. In another design, the signaling may
be precoded (or spatially processed) with a transmit steering vector and sent from
multiple antennas. In this design, the signaling may be sent from one virtual antenna
formed with the transmit steering vector. In yet another design, the signaling may
be space-time block coded and sent from multiple antennas, e.g., from two antennas
using space-time transmit diversity (STTD). The signaling may be precoded in similar
manner as traffic and pilot.
[0064] FIG. 12 shows a block diagram of a design of OFDM demodulator 560 and receive processor 570
and at access terminal 120x in FIG. 5. Within OFDM demodulator 560, a cyclic prefix
removal unit 1210 may obtain N + C received samples in each OFDM symbol period, remove
the cyclic prefix, and provide N received samples for the useful portion. A DFT unit
1212 may perform an N-point DFT on the N received samples and provide N received symbols
for the N subcarriers. A demultiplexer 1214 may provide received symbols for traffic
data and signaling to a data demodulator 1216 and provide received symbols for pilot
to a channel estimator 1218. Channel estimator 1218 may derive a channel estimate
based on the received symbols for pilot. Data demodulator 1216 may perform data detection
(e.g., matched filtering, equalization, etc.) on the received symbols for traffic
data and signaling with the channel estimate from channel estimator 1218 and provide
received data symbols and received signaling symbols.
[0065] Within receive processor 570, a tone demapper 1220 may provide the received signaling
symbols to a signaling detector 1230 and provide the received data symbols to a receive
(RX) traffic processor 1240. Tone demapper 1220 may determine the tones used for the
signaling in the same manner as access point 110x, e.g., based on all or a portion
of the MAC_ID of access terminal 120x for the designs shown in FIGS. 8, 9 and 11 and
based on a predetermined set of tones for the designs shown in FIG. 7 and 10. Signaling
detector 1230 may detect for signaling sent to access terminal 120x based on the received
signaling symbols and provide detected signaling. Within signaling detector 1230,
a metric computation unit 1232 may compute a metric for each codeword that might be
sent for the signaling. A codeword detector 1234 may determine whether any codeword
was sent to access terminal 120x based on the metric and, if a codeword was sent,
may provide the information associated with this codeword as the detected signaling.
Within RX traffic processor 1240, a unit 1242 may compute log-likelihood ratios (LLRs)
for code bits based on the detected signaling (e.g., the rate adjustment) from signaling
detector 1230. A decoder 1244 may decode the LLRs based on the detected signaling
and provide decoded data for access terminal 120x.
[0066] The received signaling symbols at access terminal 120x may be expressed as:

where
Sk is a signaling symbol sent on tone k,
Ck is a complex channel gain for tone k,
Ek is the transmit power for the signaling symbol sent on tone k,
nk is noise for tone k, and
rk is a received signaling symbol for tone k.
[0067] In one design, unit 1232 may compute a metric
Qm for each possible codeword
m for the signaling, as follows:

where
ĉk is an estimate of the channel gain for tone k,
Sk,m is a signaling symbol for tone k for the m-th codeword,
Nt is noise variance, which may be estimated, and
"*" denotes a complex conjugate and "Re" denotes the real part.
The metric in equation (2) may provide good detection performance in terms of false
alarm from the signaling for other access terminals.
[0068] In another design, unit 1232 may compute a metric
Qm for each possible codeword
m, as follows:

The metric in equation (3) may provide good detection performance in terms of false
alarm from traffic data and signaling for other access terminals and also when the
received codewords are not orthogonal.
[0069] Signaling detector 1230 may detect for signaling for each of the different possible
resource assignments for access terminal 120x. For each possible resource assignment,
unit 1232 may compute metric
Qm for each possible codeword that might be sent to access terminal 120x for the signaling.
Detector 1234 may compare the computed metric for each codeword against a threshold
and may declare a detected codeword if the metric exceeds the threshold. A single
threshold may be used for all channel scenarios, e.g., different power delay profiles,
high and low geometries/SNRs, high and low mobility/Doppler, etc. Alternatively, different
thresholds may be used for different channel scenarios. The threshold(s) may be selected
to achieve the desired false alarm probability and detection probability.
[0070] FIG. 12 shows a design of signaling detector 1230 that may be used for signaling
sent with block encoding, e.g., as shown in FIG. 7, 8, and 11. The block decoding
may also be performed in other manners. If the signaling is sent with DFT precoding,
e.g., as shown in FIG. 9, then the signaling detector may perform an IDFT prior to
the block decoding. If the signaling is sent with convolutional encoding, e.g., as
shown in FIG. 10, then the signaling detector may perform Viterbi decoding.
[0071] FIG. 13 shows a design of a process 1300 for transmitting data and signaling. Process 1300
may be performed by an access point for transmission on the downlink or by an access
terminal for transmission on the uplink. Signaling for a data transmission may be
processed, e.g., encoded based on a block code, a convolutional code, etc. (block
1312). The block code may be an orthogonal code, a bi-orthogonal code, a static block
code, a dynamic block code, a pseudo-random block code, etc. The pseudo-random block
code may be based on a PN sequence for a receiver (e.g., an access terminal) to which
the data transmission is sent or a PN sequence specific for the receiver. The signaling
may also be partitioned into multiple parts, and each part of the signaling may be
encoded with a respective code. The signaling may also be processed with a DFT or
some other transformation to spread each signaling symbol across multiple tones. The
signaling may comprise an identifier of the receiver (e.g., the access terminal),
information indicative of a data rate for the data transmission, information indicative
of resource assignment for the data transmission, etc. Data for the data transmission
may be processed, e.g., encoded, interleaved, and symbol mapped (block 1314).
[0072] The signaling for the data transmission may be mapped to a first set of tones in
a time slot (block 1318). The data for the data transmission may be mapped to a second
set of tones in the time slot (block 1316). The first and second sets of tones may
be among the tones assigned for the data transmission. The tones in the first set
may be (i) distributed across the system bandwidth and/or (i) distributed across the
time slot or located in an earlier portion of the time slot. The entire signaling
may be sent on the first set of tones, e.g., as shown in FIGS. 7 and 10. Alternatively,
the signaling may comprise first and second parts, the first set of tones may be selected
based on the first part of the signaling, and the second part of the signaling may
be sent on the first set of tones, e.g., as shown in FIGS. 8, 9 and 11.
[0073] The number of tones in the first set and/or the transmit power for the signaling
may be selected based on channel conditions for the data transmission. The time slot
may comprise one or more traffic segments time division multiplexed with one or more
overhead segments. The first and second sets of tones may be located in the traffic
segment(s).
[0074] FIG. 14 shows a design of a process 1400 for sending signaling. Process 1400 may also be
performed by an access point or an access terminal. Signaling may be partitioned into
multiple parts comprising a first part and a second part (block 1412). The signaling
may comprise any information for a data transmission, and each part may be of any
size. For example, the first part of the signaling may comprise all or a portion of
an identifier of a receiver (e.g., an access terminal) for a data transmission.
[0075] A set of tones may be selected from among a plurality of tones based on the first
part of the signaling (block 1414). The plurality of tones may be tones assigned for
the data transmission or tones available to send the signaling. The set of tones may
be selected from among multiple sets of tones based on the first part of the signaling.
The set of tones may also be pseudo-randomly selected from among the plurality of
tones based on the first part of the signaling, an identifier of a transmitter (e.g.,
an access point or cell) sending the data transmission, an index of a time slot in
which the data transmission is sent, etc.
[0076] The second part of the signaling may be encoded based on a static block code, a time-varying
block code, a pseudo-random block code, a convolutional code, etc. The second part
of the signaling may also be processed based on a DFT or some other transformation.
The second part of the signaling may be sent on the selected set of tones (block 1416).
The second part of the signaling may be sent with higher transmit power than transmit
power for data to improve reliability.
[0077] FIG. 15 shows a design of a process 1500 for receiving data and signaling. Process 1500 may
be performed by an access terminal for transmission on the downlink or by an access
point for transmission on the uplink. Received symbols for a first set of tones in
a time slot may be obtained, e.g., by performing OFDM demodulation on received samples
(block 1512). The received symbols for the first set of tones may be processed to
obtain detected signaling (block 1514). The first set of tones may be determined from
among multiple sets of tones based on an identifier of a receiver (e.g., an access
terminal). The first set of tones may also be determined from among a plurality of
tones assignable for data transmission based on the identifier of the receiver (e.g.,
the access terminal), the identifier of a transmitter (e.g., an access point or cell),
a time slot index, etc. For block 1514, a metric may be computed for each of multiple
codewords based on the received symbols. Whether any codeword was sent may be determined
based on the computed metric for each codeword. The detected signaling may be obtained
based on a codeword determined to have been sent.
[0078] Whether or not to process a second set of tones in the time slot for a data transmission
may be determined based on the detected signaling (block 1516). The detected signaling
may indicate no data transmission is sent for the receiver if none of the codewords
is determined to have been sent. If the detected signaling indicates that data transmission
is sent, then received symbols for the second set of tones may be processed to recover
the transmitted data. The second set of tones, a data rate for the data transmission,
and/or other information may be obtained from the detected signaling.
[0079] Those of skill in the art would understand that information and signals may be represented
using any of a variety of different technologies and techniques. For example, data,
instructions, commands, information, signals, bits, symbols, and chips that may be
referenced throughout the above description may be represented by voltages, currents,
electromagnetic waves, magnetic fields or particles, optical fields or particles,
or any combination thereof.
[0080] Those of skill would further appreciate that the various illustrative logical blocks,
modules, circuits, and algorithm steps described in connection with the disclosure
herein may be implemented as electronic hardware, computer software, or combinations
of both. To clearly illustrate this interchangeability of hardware and software, various
illustrative components, blocks, modules, circuits, and steps have been described
above generally in terms of their functionality. Whether such functionality is implemented
as hardware or software depends upon the particular application and design constraints
imposed on the overall system.
[0081] The various illustrative logical blocks, modules, and circuits described in connection
with the disclosure herein may be implemented or performed with a general-purpose
processor, a digital signal processor (DSP), an application specific integrated circuit
(ASIC), a field programmable gate array (FPGA) or other programmable logic device,
discrete gate or transistor logic, discrete hardware components, or any combination
thereof designed to perform the functions described herein. A general-purpose processor
may be a microprocessor, but in the alternative, the processor may be any conventional
processor, controller, microcontroller, or state machine. A processor may also be
implemented as a combination of computing devices, e.g., a combination of a DSP and
a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction
with a DSP core, or any other such configuration.
[0082] The steps of a method or algorithm described in connection with the disclosure herein
may be embodied directly in hardware, in a software module executed by a processor,
or in a combination of the two. A software module may reside in RAM memory, flash
memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable
disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary
storage medium is coupled to the processor such that the processor can read information
from, and write information to, the storage medium. In the alternative, the storage
medium may be integral to the processor. The processor and the storage medium may
reside in an ASIC. The ASIC may reside in a user terminal. In the alternative, the
processor and the storage medium may reside as discrete components in a user terminal.
1. Eine Vorrichtung, die Folgendes aufweist:
wenigstens einen Prozessor zum Abbilden von Signalisierung für eine Datensendung bzw.
Datenübertragung auf einen ersten Satz von Tönen in einem Zeitschlitz, und zum Abbilden
von Daten für die Datenübertragung auf einen zweiten Satz von Tönen in dem Zeitschlitz
wobei ein erster Teil der Signalisierung einen Identifikator für ein Zugriffsendgerät
aufweist, an welchen die Datenübertragung gesendet wird, und
wobei der wenigstens eine Prozessor den ersten Satz von Tönen aus einer Vielzahl von
Tönen basierend auf dem ersten Teil der Signalisierung auswählt
und eine Sendeleistung für die Signalisierung bestimmt, und zwar basierend auf Kanalbedingungen
für die Datenübertragung; und
einen Speicher, der an den wenigstens einen Prozessor gekoppelt ist.
2. Vorrichtung nach Anspruch 1, wobei der wenigstens eine Prozessor eine Vielzahl von
Tönen für die Datensendung zuweist und die ersten und zweiten Sätze von Tönen basierend
auf der Vielzahl von Tönen bestimmt.
3. Vorrichtung nach Anspruch 1, wobei der wenigstens eine Prozessor die Signalisierung
basierend auf wenigstens einem von einem Orthogonalcode, einem Bi-Orthogonal-Code,
einem Blockcode, einem zeitlich variierenden Blockcode, einem pseudozufälligen Blockcode
und einem Faltungscode codiert.
4. Vorrichtung nach Anspruch 1, wobei der wenigstens eine Prozessor die Signalisierung
basierend auf einem pseudozufälligen Blockcode codiert, der basierend auf einer Pseudozufallszahlsequenz
bzw. PN-Sequenz (PN = pseudo-random) für ein Zugriffsendgerät, an welches die Datenübertragung
gesendet wird, bestimmt wird.
5. Vorrichtung nach Anspruch 1, wobei der wenigstens eine Prozessor die Signalisierung
in mehrere Teile partitioniert, jeden Teil der Signalisierung mit einem entsprechenden
Code codiert, und mehrere codierte Teile der Signalisierung auf dem ersten Satz von
Tönen sendet.
6. Vorrichtung nach Anspruch 1, wobei der wenigstens eine Prozessor die Signalisierung
mit einer diskreten Fourier-Transformation bzw. DFT (DFT = discrete Fourier transform)
oder einer unitären Transformation vor dem Abbilden auf den ersten Satz von Tönen
verarbeitet.
7. Vorrichtung nach Anspruch 1, wobei der wenigstens eine Prozessor einen zweiten Teil
der Signalisierung auf dem ersten Satz von Tönen sendet.
8. Vorrichtung nach Anspruch 1, wobei der wenigstens eine Prozessor die Anzahl von Tönen
in dem ersten Satz basierend auf Kanalbedingungen für die Datenübertragung auswählt.
9. Vorrichtung nach Anspruch 1, wobei der wenigstens eine Prozessor die Signalisierung
mit einem Sendesteuer- Sende-Steering-Vektor oder einem Raum-Zeit-Blockcode vor einer
Sendung bzw. Übertragung über mehrere Antennen verarbeitet.
10. Vorrichtung nach Anspruch 1, wobei die Datensendung für ein Zugriffsendgerät ist,
und wobei die Signalisierung weiter Folgendes aufweist:
Information, die eine Datenrate für die Datensendung anzeigt und/oder Information,
die eine Ressourcenzuweisung für die Datenübertragung anzeigt.
11. Vorrichtung nach Anspruch 1, wobei die Töne in dem ersten Satz über eine Systembandbreite
hinweg verteilt sind.
12. Vorrichtung nach Anspruch 1, wobei die Töne in dem ersten Satz in einem frühen Abschnitt
des Zeitschlitzes angeordnet sind.
13. Vorrichtung nach Anspruch 1, wobei der Zeitschlitz wenigstens ein Verkehrssegment
aufweist, das mit wenigstens einem Overhead-Segment zeitlich gemultiplext ist, und
wobei die ersten und zweiten Sätze von Tönen in dem wenigstens einen Verkehrssegment
angeordnet sind.
14. Ein Verfahren, das Folgendes aufweist:
Abbilden von Signalisierung für eine Datensendung bzw. Datenübertragung an einen ersten
Satz von Tönen in einem Zeitschlitz; und
Abbilden von Daten für die Datenübertragung auf einen zweiten Satz von Tönen in dem
Zeitschlitz; und
dadurch gekennzeichnet ist, dass ein erster Teil der Signalisierung einen Identifikator für ein Zugriffsendgerät aufweist,
an welches die Datenübertragung gesendet wird, und wobei das Verfahren weiter den
Schritt des Auswählens des ersten Satzes von Tönen aus einer Vielzahl von Tönen basierend
auf dem ersten Teil der Signalisierung aufweist und Bestimmen einer Sendeleistung
für die Signalisierung basierend auf Kanalbedingungen für die Datensendung.
15. Ein Computerprogrammprodukt, das Folgendes aufweist:
Code, der, wenn er durch einen Computer ausgeführt wird, den Computer veranlasst zum
Durchführen des Verfahrens nach Anspruch 14.
1. Dispositif comprenant :
au moins un processeur pour mettre en correspondance la signalisation pour une transmission
de données à un premier ensemble de tonalités dans un intervalle de temps, et pour
mettre en correspondance des données pour la transmission de données avec un second
ensemble de tonalités dans l'intervalle de temps
dans lequel une première partie de la signalisation comprend un identifiant pour un
terminal d'accès auquel la transmission de données est envoyée, et
dans lequel l'au moins un processeur sélectionne le premier ensemble de tonalités
parmi une pluralité de tonalités sur la base de la première partie de la signalisation
et détermine la puissance d'émission pour la signalisation sur la base des conditions
de canal pour la transmission de données ; et
une mémoire couplée à l'au moins un processeur.
2. Dispositif selon la revendication 1, dans lequel le au moins un processeur affecte
une pluralité de tonalités pour la transmission de données et détermine les premier
et second ensembles de tonalités sur la base de la pluralité de tonalités.
3. Dispositif selon la revendication 1, dans lequel le au moins un processeur code la
signalisation sur la base d'au moins l'un parmi un code orthogonal, un code bi-orthogonal,
un code de bloc, un code de bloc variant dans le temps, un code de bloc pseudo-aléatoire
et un code de convolution.
4. Dispositif selon la revendication 1, dans lequel le au moins un processeur code la
signalisation sur la base d'un code de bloc pseudo-aléatoire déterminé sur la base
d'une séquence de nombres pseudo-aléatoires (PN) pour un terminal d'accès auquel la
transmission de données est envoyée.
5. Dispositif selon la revendication 1, dans lequel le au moins un processeur partitionne
la signalisation en plusieurs parties, code chaque partie de la signalisation avec
un code respectif et envoie plusieurs parties codées de la signalisation sur le premier
ensemble de tonalités.
6. Dispositif selon la revendication 1, dans lequel le au moins un processeur traite
la signalisation avec une transformation de Fourier discrète, DFT, ou une transformation
unitaire avant la mise en correspondance avec le premier ensemble de tonalités.
7. Dispositif selon la revendication 1, dans lequel l'au moins un processeur envoie une
seconde partie de la signalisation sur le premier ensemble de tonalités.
8. Dispositif selon la revendication 1, dans lequel l'au moins un processeur sélectionne
le nombre de tonalités dans le premier ensemble en fonction des conditions de canal
pour la transmission de données.
9. Dispositif selon la revendication 1, dans lequel le au moins un processeur traite
la signalisation avec un vecteur de direction de transmission ou un code de bloc espace-temps
avant la transmission via plusieurs antennes.
10. Dispositif selon la revendication 1, dans lequel la transmission de données est destinée
à un terminal d'accès, et dans lequel la signalisation comprend, en outre, une information
indicative d'un débit de données pour la transmission de données et/ou une information
indicative d'une affectation de ressource pour la transmission de données.
11. Dispositif selon la revendication 1, dans lequel les tonalités du premier ensemble
sont réparties sur la largeur de bande du système.
12. Dispositif selon la revendication 1, dans lequel les tonalités du premier ensemble
sont situées dans une partie avancée de l'intervalle de temps.
13. Dispositif selon la revendication 1, dans lequel l'intervalle de temps comprend au
moins un segment de trafic multiplexé dans le temps avec au moins un segment de gestion
(overhead), et dans lequel les premier et second ensembles de tonalités sont situés dans le
au moins un segment de trafic.
14. Un procédé comprenant les étapes consistant à :
mettre en correspondance la signalisation pour une transmission de données avec un
premier ensemble de tonalités dans un intervalle de temps ; et
mettre en correspondance des données pour la transmission de données avec un second
ensemble de tonalités dans l'intervalle de temps ; et
caractérisé en ce qu'une première partie de la signalisation comprend un identifiant pour un terminal d'accès
auquel la transmission de données est envoyée, et dans lequel le procédé comprend
en outre l'étape consistant à sélectionner le premier ensemble de tonalités parmi
une pluralité de tonalités sur la base de la première partie de la signalisation et
la détermination de la puissance d'émission pour la signalisation sur la base des
conditions de canal pour la transmission de données.
15. Un produit formant programme d'ordinateur, comprenant :
du code, qui, lorsqu'il est exécuté par un ordinateur, amène l'ordinateur à exécuter
le procédé selon la revendication 14.